Congratulations, Paul.

 

I think quite a bit more. I'd have had to do everything I did plus disassembling the idler pully, brackets and belt that are situated where the US airpump is. I'm not even sure if I would have to disconnect the coolant pipe on that side to get it through the space.

However, on a US car, you also need to consider how to access the top pivot bolt nut at the rear end of the alternator. If you can't access that without removing the airpump, then you might have to dismantle so much stuff at the top end anyway that top-end removal is easier?

If I hadn't been able to get it through the gap at the bottom, my next step would have been to loosen the front clamps of the anti-roll bar and see if that gave me just a touch more space to get it through the bottom gap. It would still have been easier than trying from the top.

Overall, I'd still suggest that taking out from the bottom is the preferred route.

Paul

 

Having taken the alternator to my local auto electricians, it seems I have 2 options:

- Either he can test it, verify the causes of the problems and any other problems with the unit and fix it for me. OR
- He can supply me a new pattern unit.

He knows these Denso alternators well and had previously rebuilt the same basic unit on my 4 litre a few years ago. He suspects it might need the diode pack, as the regulators are a common failure. Of course there is the potential for bearing wear etc. He is estimated the cheapest it would be including test, labour and parts is £85, rising to £150, if bearings etc also require attention.

Alternatively he can get me a replacement new pattern unit in 24 hours (no exchange required) with a 2-year guarantee (not really relevant as the car is being sold) apparently from a reputable Dutch supplier. The cost would be £120.

I have to have the car running next week to get it to auction, so I'm thinking the pattern replacement seems the easiest option?

Of course, if I then find it was a wiring loom problem not an alternator problem, I've wasted the money....

What would you do in my shoes?

Paul

 

Given the timing of the auction, I'd go with replacement.

 

I think I'd go with the replacement as well, as you're in a hurry and don't really care if it lasts longer than the auction.

 

It's the alternator, Paul, not the wiring. Additionally, it will take your repair guy about 5 mins to test the old alt and confirm it is shot.

 

Thank you for your input Guys. I've decided and ordered in the new unit. At least I can leave the original with the car for rebuild should the new owner really want originality in the future.

And thanks for your confidence, Greg, that it will be the alternator not the wiring. Without wanting to incur any more cost even testing the old unit, my aut-electrician has said that knowing the background of the car, he'll be 95% sure it will be a failed unit. So, the die is cast now.

I'll post pics of the install next week, which may help other owners when it comes to removal of their own units.

Cheers

Paul

 

Well it's not quite gone according to plan.

When I picked up the new alternator, it was clear that the electrical terminals were on the other side on the rear case. This clarified, as I'd heard, that Jaguar had commissioned a different configuration from Denso when they fitted the 120amp version to the V12, that was being fitted to the 4 litre cars. You can see the difference in the photo below.

They said they couldn't find an option from their suppliers to get one of the correct configuration, so I agreed to try and fit the new alternator supplied. But it soon became apparent that not only would it be difficult if not impossible to fit the alternator with the wiring attached, the positions of the terminals would be dangerously close to other metal components in the engine bay.

So, I returned it and they are currently in the process of reconfiguring it to get the terminals in the correct position. The only positive thing is that they tried to use some of the internals of the original alternator and, in testing it, they identified that the shaft was broken (electrically), so whilst that means more work to reconfigure the new one, at least I know that the old alternator really was faulty.

I should be able to get the reconfigured item tomorrow and we'll go from there.

Paul

 

Eventual success! ( I believe....!)

After delays in getting the new alternator rebuilt by the supplier to place the terminals in the correct orientation, and then further delays in getting it delivered, I finally got it today and headed off to try and install it. After all the problems in getting it out, I really wasn't looking forward to this. This is the order in which I did the install:

The alternator needs to be one like this, with the terminals on the right hand side when viewed from inside the car. Do not try and fit the same-type alternator from a 4 litre which has the terminals on the left side: Obviously have the battery disconnected before you start.





The alternator goes in from the bottom between the subframe and the anti-roll bar. This is the gap you're looking at:




You need to turn the alternator into this orientation and then just squeeze it upwards through the gap:




You then turn the alternator around to start positioning the pulley to the front:






Now comes the really difficult bit, trying to push the alternator up into the top pivot gap and install the pivot bolt from underneath into the pivot. With the other belts still in place, and doing it on your own, it's almost impossible. It would be much easier if someone could try and manoeuvre the bolt in from above. In addition, there's a sleeve in the front top pivot hole shoulder which protrudes slightly into the pivot gap. This makes positioning the alternator into the pivot gap even more difficult, if that were possible!. I spent 2 hours last night with a piece of threaded stud, a socket and nuts and washers trying to pull the sleeve forward to give me fractionally more room to push the alternator into place today. The position of the pivot bolt is shown here looking from below:



With the pivot bolt eventually pushed through both shoulders, I then loosely hooked the belt over the pulley:



I then headed to the top to fit the electrical terminals. The end of the pivot bolt is shown here awaiting the securing nut to be fitted:



I then fitted the pivot bolt rear nut and washer, still loosely awaiting final belt tensioning, I then fitted the multi-pin plug which clicks into place:



I then attempted to fit the eyelet by first dropping the nut which disappeared somewhere on top of the subframe out of sight. So I spent 25 minutes with a telescopic magnet trying to find it which miraculously eventually I succeeded. I suggest you skip these last 2 activities if you can possibly help it! It' was a very depressing part of the evening!
I finally fitted the eyelet terminal but didn't fully tighten it as the alternator needed to be pivoted and tightened first before fully securing the eyelet terminal and not stretching the wire:




Back down below I then refitted the adjustment plate and linkage, first bolting it to the engine, and then bolting it to the alternator. Naturally you should slacken off the adjustor nuts before fitting and then finally tension it correctly using the nuts and bolt everything up tight:




Back up top again, I then tightened the rear pivot bolt nut. This can be really difficult trying to hold the front bolt head to pull the front sleeve into place and tighten the nut at the rear. The belts at the front, and lack of space at the back, mean you have to use spanners rather than sockets. The access to the front bolt from above is so obscured that I couldn't even get a photo of the bolt head. I then did a final tighten of the electrical eyelet terminal and fitted the rubber boot.



Before doing a final install of the body X-brace and the spoiler closing panel, I took a deep breath, connected the battery, turned the key and....the engine started immediately and I measured the voltage at the battery at 14.2 volts at a fast idle!!! And even the voltmeter in the car registered about 14.5 volts! Despite all the efforts I'd made, I admit I was incredibly surprised that it seems to have finally gone ok!

In summary, a few thoughts:

- It's possible (and preferable) to take a 6 litre alternator out the bottom of the car, but it's laborious!
- It is possible to remove and refit it on your own, but it's lonely and difficult. Find an assistant for actual and moral support!
- Make sure you get your own alternator rebuilt or be absolutely sure you get the correct replacement one. Do not buy a 4 litre one and try and fit that.

Thanks for all your thoughts and input Guys! I got there in the end! I then did an engine oil and filter change and the car now goes off to auction on Monday!

Cheers

Paul

 

Many congratulations, Paul. You have passed the apprentice stage of your Jaguar V12 education with flying colours, with a special mention for persistency and sticktoitiveness.

 

Paul
OFF TOPIC:
Your inbox is full! My last PM filled it. You need to delete a few old ones to allow new ones to arrive.
This was what I could not send:

"Worth renewing the cap if nothing else changes the leak!"

 

Tks Greg,

Sorted messages & sent you a reply.

Paul

 

Hey Greg,

It's your turn to run out of message storage space, apparently!

Paul

 

Thanks, Paul, just fixed!